The sequenced addition of RLi to nitriles, trapping with isopropylformate, and dehydration with phosphoryl chloride provides an efficient, direct synthesis of alkene isocyanides. The one‐pot sequence involves a series of carefully orchestrated steps: addition, formylation, tautomerization, and dehydration, with CuCN catalyzing a key equilibration of a formyl imine to an N‐formyl enamine. The resulting aromatic alkeneisocyanides, that are otherwise challenging to synthesize, engage in an unusual [4+2]‐type cycloaddition/1,3‐H shift/decyanation sequence to afford substituted naphthalenes.
An orchestrated sequence: An efficient synthesis of alkeneisocyanides is achieved through the sequenced addition of RLi to nitriles, formylation, and dehydration. A key step in this one‐pot sequence is a CuCN‐catalyzed equilibration of a formyl imine to an N‐formyl enamine. The utility of the reaction is illustrated in a new [4+2]‐type cycloaddition/1,3‐H shift/decyanation.